An automotive spoiler attached to a vehicle prevents the vehicle from aerodynamic lift and drag due to wind pressure or air pressure in a specific driving situation of the vehicle such as high-speed running or cornering, and improves fuel efficiency.
When the vehicle is in motion, it undergoes various types of resistance. For example, there is air resistance acting in an opposite direction on the vehicle running forward under an influence of aerodynamic flow around the vehicle.
In general, the air resistance is caused by a pressure difference due to air hitting the front of the vehicle. When the vehicle is lifted by a vortex of air at a rear part of the vehicle, a contact force between tires and the ground decreases, and thus, the vehicle cannot increase the speed and becomes unstable.
In order to prevent such lifting, the spoiler changes air flow by spoiling vortexes at a rear side of the vehicle by pressing the rear side of the vehicle.
An existing automotive spoiler has a wing fixed at a predetermined angle, and thus the spoiler cannot effectively manage airflow changes due to a speed change of the vehicle and has a limit in ensuring running stability of the vehicle. To solve this problem, a spoiler (adjustable spoiler) that can automatically adjust an angle has been recently proposed.
Referring to FIGS. 5A and 5B, an existing adjustable spoiler has an angle (positions) controlled in accordance with a vehicle speed. The spoiler according to the related art is operated when the speed is a predetermined speed or more but not operated when the speed is below the predetermined speed. The spoiler is controlled in a step-by-step mode to change a position of the spoiler step by step in accordance with the vehicle speed.
However, the existing adjustable spoiler as described above may be designed without considering an actual wind pressure applied to the spoiler while a vehicle is in motion, and a position of such a spoiler is fixed within a predetermined speed range. Thus, it is difficult to control the position of the existing adjustable spoiler against large drag and lift. Further, a specific control logic for controlling the position of the spoiler is required to control the drag and lift simultaneously, which have conflictive aerodynamic properties, and thereby design becomes complicated
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may include information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.